Storage-battery grid



Patented July 3, 1928.

UNITED STATES REGINALD SCOTT DEAN, OF LA GRANGE, ILLINOIS, AND WILLIAM EWART HUDSON, O15

PATENT OFFICE.

LOS ANGELES, CALIFORNIA, ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCOR- PORATED, OF NEW YORK, N. Y.,"A CORPORATION OF NEW YORK.

STORAGE-BATTERY GRID.

No Drawing. Application filed February 5, 1924, Serial No. 690,720. Renewed September 27, 1927.

An object of this invention is to producea storage battery grid of high lead content having greater hardness and tensile strength than has heretofore been possible in such an alloy.

A further'objecLof this invention is to produce a lead-alloy storage battery grid of low alloying content with increased tensile strength and hardness and maximum resistance to corrosion.

Storage battery grids are usually made of lead, into which some alloying matter is added to increase the hardness and tensile strength of the lead. A common alloy employed. consists of about 90 per cent lead and 10 per cent antimony.

In our co-pendingapplication, Serial No. 090,716, filed February 5, 1924, a method of greatly increasing the hardness and tensile strength of lead by adding a small amount of alloyin matter and subjecting the alloy to a hardening treatment is disclosed. It is sufficient to state here that the process consists briefly in adding'alloying matter to lead which has a greater solubility at a higher temperature than at a lower temperature. A solid solution is formed at the higher temperature and the alloy quenched to a lower temperature, to'

form a supersaturated solution, and subsequently allowed to age. A process for manufacturing storage battery grids according to this method is as follows The lead and antimon are prepared preferably in proportions 0 97.75 per cent lead and 2.25 per cent antimony and cast into the form of an ingot and formed, therefrom into the shape of the grid desired. It is sometimes advantageous to roll the ingot into a flat sheet and then stamp the grid of proper proportions therefromm After the grid has been formed in this manner its alloy constituents are usually found to be in the form of a solid solution of antimony in lead. If, however, the work performed on the alloy and the temperature maintained during the work have not been sufficient to cause the alloy to become a homogeneous solid solution, the grid must be heated until a solid solution is formed. This formation of the solid solution may be carried out in the manner set forth in detail in the co pending application mentioned above. After the grid has been formed and its alloy constituents reduced to a solicbsolution it is quenched and aged. Quenching in water at room temperature has been found sufficiently efficacious, as such a temperature is low enough to accomplish the desired result, and is easily maintained. Aging may take place at temperatures below about 100 C. but above about 0 C. For

practical purposes, about 20 C. is suflicient. If aged at room temperatures, good results are found to be obtained in about 72 hours.

The preliminary steps in this process may be varied as follows:-

Lead and antimony preferably in the pro portions of 97.75 per cent lead and 2.25 per cent antimony are melted together and when in an entirely molten state are cast into the form required. When solid they are heated until a substantially homogeneous solid solution is formed, quenched and aged. Hardening may be obtained with percentages of antimony between about 1 per cent and 3 per cent but greatest hardness is obtainable with about 2.25 per cent antimony.

A storage battery grid produced according to this-method from an alloy of 97.75

per cent lead and 2.25 per cent'antimony,

the effect of diminishing the time required to reduce the alloy to a solid solution by heating. This fact'can be made use of in the manufacturing of storage battery grids.

For more specific details of a process for hastening the formation of a solid solution by work during the progress of fabrication, reference ma be made to our .copending application 0. 690,719, filed February 5, 1924.

By practicing the above outlined method, storage battery grids may be produced which in their finished form consist of a lead alloy battery grids result from the extreme smallness of the particles of the solute material and to the uniformity of their dispersionthroughout the lead.

This invention is not confined to the use of antimony as solute. Any alloying matter having the desired qualities as indicated in our copending application mentioned above ma be used.

iat is claimed is:

1. A storage battery grid formed of a lead alloy in which lead is the major constituent, characterized by the presence of finely divided particles-of a solute material substantially uniformly dispersed throughout the lead.

2. A storage battery grid formed of a lead-antimony alloy in which lead is the major constituent, characterized by the presence of finely divided particles of antimony substantially uniformly dispersed throughout the lead.

3. A storage battery grid formed of a lead-antimony alloy containing less than 3 per cent antimony, and characterized by the presence of finely divided particles of antimony substantially uniformly dispersed throughout the lead.

4. A storage battery grid formed of a lead-antimony alloy containing about 2.25 per cent antimony, and characterized by the presence of finely divided particles of antimony substantially uniformly dispersed throughout the lead.

In Witness whereof, We hereunto subscribe our names this 22nd day of January A. D., 1924.

REGINALD SCOTT DEAN. WILLIAM EWVART HUDSON. 

